Dick Advocaat has revealed he wants up to four more summer signings as he attempts to rebuild his Sunderland team.

The 67-year-old Dutchman agreed to return to the Stadium of Light as head coach last month after initially rejecting the opportunity to reprise his nine-game cameo at the end of last season, during which he guided the club away from relegation trouble and ultimately preserved their Barclays Premier League status.

Chairman Ellis Short promised to fund a summer rebuilding programme in the wake of the Black Cats' recent struggles, and sporting director Lee Congerton has already secured the services of Liverpool central defender Sebastian Coates and Celtic full-back Adam Matthews, as well as tying up key midfielder Lee Cattermole on a five-year contract extension.

However, Advocaat, who is insisting on quality rather than quantity, knows there is still work to be done before he has a squad which can compete in the area of the league he believes Sunderland's status demands.

Asked how many more signings he wants, he said: "Three, maybe four.

"It is still very quiet on the transfer market, in England as well. It's strange. But we still hope that we can get three extra players in the squad. That makes everything a little bit easier.

"What I have said already - and we discussed it with Lee and with the president at the end of last season - we need more competition in the squad.

"We now have two with Coates and Matthews, but hopefully we will still try to get some other ones in as well.

"We are all working very hard to get the right players in, but that is not so easy.

"Everybody thinks abroad that England is the country of the money, so we have to be very careful with the money, we have to bring the right players in who can compete with the other players. "

Sunderland are understood to be pursuing a series of targets with Zenit St Petersburg defender Nicolas Lombaerts, Dynamo Kiev's Jeremain Lens and West Ham's Stewart Downing among them, although Advocaat was giving nothing away.

He said: "I can only tell you things if I know 100 per cent when they are coming, because now I start saying all the good things and maybe tomorrow they say they didn't do it.

"Let's wait and see what happens in the next days and weeks."

Advocaat's comments came as he met the media for the first time since belatedly accepting Short's offer of employment.

The former Holland boss had promised his wife he would retire after his short spell on Wearside, but the club's constant probing eventually prompted Mrs Advocaat to grant her permission for a rethink.

Asked what convinced him to return, Advocaat said with a smile: "Money.

"No, the most important thing was that the family was happy after a certain moment.

"The club tried to convince me every day and she was listening and listening, and I said, 'No, I won't do it' - you know the history.

"But at a certain moment, she said, 'If you still want to do it, then just do it', and that was the moment.

"Lee was pushing every day, and the president. At a certain moment everybody was convinced that for one year or two years, it was better for me to go on instead of sitting at home."

So grateful were the club's fans that they raised in excess of £2,000 to buy flowers for Advocaat's wife, much to her husband's amazement.

He said: "It was something special also to her, and that says enough about the club."

Sunderland begin their pre-season programme against Darlington at Bishop Auckland on Thursday evening before jetting out to the United States at the weekend.